This invention relates to radiant energy collection devices and in particular to solar energy collectors utilizing air or a similar fluid as the heat transfer media.
Many different solar collector devices have been developed in the prior art for collecting and utilizing radiant energy received from the sun. Typically, such prior art devices are rectangular boxes having glass or other light transparent surfaces suspended above a solar absorbing surface which is oriented to absorb sun rays. In these collectors a fluid is passed in heat exchange relationship with the solar absorbing surface. Such collector devices are known as flat plate collectors.
Some flat plate collectors utilize a liquid such as water as the heat transfer medium. Among the disadvantages of flat plate collectors employing a liquid as the heat transfer medium is the need for extensive plumbing, liquid circulating pumps, and the like, in order to transfer the heat from the point of collection to the point of use. These necessary components add significantly to the cost of utilizing such a solar radiation system.
Another type of flat plate collector uses a fluid such as air as the heat transfer medium. Among the problems encountered in flat plate collectors utilizing air as the heat transfer medium is the need to provide for sufficient turbulence of the air in the flat plate collector to assure good heat transfer. Additionally, means are required to prevent heat loss by convection backwardly through the transparent member of the collector.
Both types of flat plate collectors have additional deficiencies in that, in order to provide a collector with a large enough heat absorption surface, it has been necessary in the past to assemble a plurality of flat plate collectors to provide a collector area large enough to satisfy the requirements of a particular building. Since each flat plate collector has its own housing and insulation, this modular construction provides for a degree of flexibility but at the expense of weight and cost of the overall solar collector assembly. Obviously not all roof structures will be able to support such significantly high weights from joining many collector modules; and, to construct a roof structure which will support the weight adds to the expense of the solar energy system.
Thus, there remains a need for a solar collector unit which is more economical and efficient than collectors encountered in the prior art.